/*
 * Licensed to Crate under one or more contributor license agreements.
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.  Crate licenses this file
 * to you under the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.  You may
 * obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 * implied.  See the License for the specific language governing
 * permissions and limitations under the License.
 *
 * However, if you have executed another commercial license agreement
 * with Crate these terms will supersede the license and you may use the
 * software solely pursuant to the terms of the relevant commercial
 * agreement.
 */

package io.crate.expression.reference.sys;

import io.crate.metadata.RowContextCollectorExpression;

import java.util.List;

public abstract class ArrayTypeRowContextCollectorExpression<RowType, IterType, ReturnType>
    extends RowContextCollectorExpression<RowType, ReturnType[]> {

    protected abstract List<IterType> items();

    protected abstract ReturnType valueForItem(IterType input);

    @Override
    @SuppressWarnings("unchecked")
    public ReturnType[] value() {
        List<IterType> items = items();
        ReturnType[] returnItems = (ReturnType[]) new Object[items.size()];
        for (int idx = 0; idx < items().size(); idx++) {
            returnItems[idx] = valueForItem(items.get(idx));
        }
        return returnItems;
    }
}
